Marine craft



Sept. 13, 1932. E. E. BALDWIN MARINE CRAFT Originl Filed Nov. 12. 1929 5Sheets-Shet 1 INVEN O I I I ATTORNEY P 13, -7 E. E. BALDWIN v MARINECRAFT Original Filed Nov. 12. 1929 5 Sheets-Sheet 2- ATTORNEY I B 8gAgnew-:21 G u.

Sept. 13, 1932. BALDWlN 1,877,380

- MARINE CRAFT Original Filed Nov. 12.- 1929 5 Sheets-Sheet 3 ATTORN EYSept. 13, I932.

E. E. BALDWIN MARINE CRAFT 5 Sheets-Sheet 4 Original Filed Nov. 12. 1929ATTORNEY Sept. 13, 1932.

E. E. BALDWIN MARINE CRAFT Original Filed Nov. 12. 1929 s sheetsrsne et5 ATTORNEY Patented Sept. 13, 1932 PATENT OFFICE.

EDWARD E. BALDWIN, OF NEW YORK, N. Y. I

MARINE CRAFT Application filed November 12, 1929, Serial No. 406,604.Renewed January 29, 1932.

This invention relates to marine craft, and

boats; some of the objects being to increase the efliciency of the powerexpended, there- L by increasing the speed; the reduction of turbulencein the liquid and the elimination of hammer blows on the hull bottom;the reduction of friction or adhesion of water to the hull bottom; thereduction of head wind pressure, while increasing the stability of thehull and the manageability by the ease with which the craft holds astraight course; and the elimination-of side Wake and spray; all 5 beingdesirable results for the general improvemeiit of commercial andpleasure craft.

In seeking to attain these objects successfully, my invention makes useof a hull, having a stream line upper body and a bottomv system ofplaning surfaces, which are so ar-' ranged that while being a type ofstream line formation in themselves, their action on the fluids as thecraft moves forward, sets up a reverse secondary stream line formationin the fluids or liquid over which the hull rides; with a resultingdecrease in. turbulence, friction, side wake, spray, etc, of the fluidson the hull bottom. so The invention is primarily predicated moreover onthe novel idea of using advantageously the head wind pressure,effectively diverting the direction ofthis wind pressure to a pointbetween the exterior bottom surfaces of the hull and the waterthereunder.

This air stream interposed under the hull body becomes part of thesecondary fluid streamline formation set up by the aforesaid arrangementof planing surfaces, while 4 -";-sorbing the turbulence of water againstthe hull bottom, and converts this turbulence into skin friction. Alsoareduction in friction is obtained by substituting an air surface forwater surface'on the hull bottom, the air secondary fluid streamlineformation of the combined fluid over which the hull moves, a greatamount of the commotion, or turbulence, caused in the water by thehydroplane typeof hull is avoided. The side wake,.or

lubricating the hull bottom. Owing to the:

back drag, is entirely eliminated by the above methods of construction.

I'have found in actual experiments that the following construction iseffective. A hull streamlined above the freeboard; and, placed forwardin the hullsurface, an opening leading to an air chamber within the bowof the hull to provide an entrance and a containing means for head windpressure, the aforesaid opening combined with shutters as a means forgraduating the quantity of air entering the chamber. Means are used forcontrolling said air in the chamber consisting of a conoidal wheelrevolving in a plenum chamber, with exit means on the hull bottom in theform of a step outlet, which step divides the bottom planing surfacesinto forward and aft sections. The forward section has a centralcutwater with concave surfaces to edges of the hull sides. These edgesjoining the sides of the hull are lower than the apex of theconcavities, as a meansof directing a current flow inwardly, toward theapex of concavity, and outwardly from the cutwater.

The concave surfaces spiral downwardly in a graduated radius ofcurvature to the terminus of the planing angles. The concavity of thesurfaces also is graduated, diminish ing towards the terminus of theplaning an gles, therefore the planing surfaces act as channels fordirecting the fluid and liquid in a current stream under the hullbottom, The terminus of the planing angles become the flat lower surfaceof the step, or air outlet means. The aft planing surfaces extend fromthe vertical side of the step to the stern and are formed in twosurfaces with the apex of the angle at the keel line of the hull and theouter edges joining the sides of the hull level with the lowest side ofthe step. Therefore, aft of the step, when the hull moves forward, afour sided pocket or suction space is formed. The vertical side of thestep is to a great extent open to allow air to enter into the suctionpocket. Two sides are formed by the =inverted V of the angularly placedplaning surfaces and the lower or fourth sideis formed by the liquid.The aforesaid pocket i'sa means to facilitate the hull in attaining aposition in the Water offering the least resistance to its forwardprogress, owing to the buoyancy, or lifting power, of the air; and thepocket is a suction space to facilitate the air means within the hull indelivering the air through the step into the pocket and between theexterior surfaces of the hull bottom' and water thereunder and withoutdestroying the current flow of either fluid or liquid.

The apex of the inverted V of the aforesaid aft planing surfaces extendsto the stern of the hull, said angle conveying the air in a steamformation from step to its discharge from under the hull directly aft ofthe stern as wake. The aforesaid inverted V type planing surfaces aregraduated from step to stern and the angle is more acute towards thestern with the apex of said angle at the keel line of the hull andtilting upwardly towards the stern; and the edges of the surfaces jointhe sides of the hull level with the bottom of the step air exitopening. As the craft moves forward in the water which contacts theouter portion of the angular surfaces adjacent to the air stream, acurrent flow is caused in the water with a tendency to. glance towardsthe air stream, the tendency increasing towards the stern of the hullbottom.

Thewater owing to the glancing inward motion is turned in one directionand the hull does not hit the water a direct blow and scatter it in alldirections; thereby the passage of the hull through the water causes aminimum of turbulence and no side wake and spray. The water glancinginwardly meets the air stream which further reduces the turbulenceagainst the hull bottom by absorbing and cushioning the hull bottom.

The combined surfaces of the inverted V type bottom direct the currentflow in the combined fluids into a stream formation or secondary fluidstreamline formation harmonious in line to the hull formation, therebyreducing turbulence into skin friction on the hull bottom; the skinfriction is further reduced by substitution of air surface for watersurface. All of the wake is discharged from underneath the hull directlyaft of the stern, and disregarding the action of the propeller on thewater, is the tail or concave trailing edges of a fluid streamline body.This wake rapidly disappears as it is white water heavily charged withair.

While I have carefully described certain successful embodiments of themain features of my invention, I wish it distinctly understood that whatI have presented is only a specimen or example of the many' forms whichthe invention mi ht assume, and I do not wish to be restricted to theprecise form or the examples herein offered, because the configurationand features combined there:

with may be greatly modified without depart ing from the inventionclaimed.

In the accompanying drawings illustrating my invention:

Figure 1 is a top plan view of my improved marine craft.

Figure 2 is a side elevation of the same.

Figure 3 is a longitudinal central section of the same.

Figure 4 is a bottom plan view, delineating the action of the currentsof air and water.

Figure 5 is a similar bottom plan view, delineating more particularlythe shape of the bottom of the hull.

Figure 6 is a partial or fragmentary side elevation at the front end.

Figure 7 is a rear end elevation.

Figure 8 is a front elevation of the same.

Figure 9 is a cross section on the line 9, 9,

of Figure 3.

Figure 10 is a cross section on the line 10, 10, of Figure 3.

Figures 11 and 12 are diagrammatic views indicating the shape of thefront concave re cesses in the bottom of the bow of the hull from thefront end back as far as the air outlet opening.

Figures 13 and 14 are similar diagrammatic views indicating the shape ofthe inverted V-bottom of the hull from the air outlet to the stern.

Figure 15 is a fragmentary perspective of the bow portion of the boat,somewhat diagrammatically expressed.

Figure 16 is a small plan view'of my improved form of boats in outlineto indicate the streamline action of the boat in the water in forming astraight wake at the stern.

Figure 17 is a similar plan view in outline of the common form of boatwith a pointed bow and the usual hull that creates lateral turbulentareas to obstruct its progress, this being shown in contrast with myimproved construction indicated in Figure 16.

Similar characters of reference designate corresponding parts in all thedifferent figures of the drawings.

1 denotes the hull of any type of marine vessel, given as anillustrative specimen only, the shape of which hull may obviously varywithin wide limits. The particular-example of hull shown is that of amodern high speed motorboat. The hull 1 is a streamlined hull above thefreeboard, to reduce wind resistance, and is preferably fashioned on itsupper longitudinal surface with narrow sections la that curve downwardlyat the bow into the blunt nose 2, such sectional surface being similarin appearance to certain kinds of streamlined dirigible air ships, butobviously this construction may be altered as desired.

7 denotes the rumble or pit, wherein is one or more seats at 8, or acabin structure may be provided instead if preferred. 9 denotes anengine or motor; 10 a shaft driven by said engine and carrying a bladedpropeller 11, be-

sides being forwardly connected to actuate a fan mechanism 12; 13 therudder or rudders; and 14 a steering wheel to control the position ofthe rudder through suitable cables or other connections.

All these features may be arranged in connection with the hull andrelated to each other in position and function in the most convenientand approved manner, and I do not wish to be restricted to any preciseplans. Also the steering wheel 14 is adjacent to the instrument board ordash in pit 7, which may carry all the usual or desired indicators,gauges, pointers, and other devices and controls.

.In order to more fully contrast the per formance of my improved contourof hull with old and well known forms, I have indi cated my improvedboat at A in Figure 16, and the boat commonly in use today at A in Fiure 17. The boat A creates the lateral elds of foam, turbulent agitationor side wakein the liquid known as back drag and hammer blows and whichtake power to produce, thereby causing loss of speed. My improved boatA, with its novel arrangement of bottom planing surfaces and aircushioning and absorbing process, first reduces the size of theturbulent field of water to that surface directly underneath the hullbottom, thereby eliminating all side wake or spray; second, 'theturbulence in the liquid is converted into skin friction by the combined action of the planing surfaces of the hull bottom and the airstream, thereby eliminating hammer blows and back drag to a greatextent; third, reducing the friction to a minimum by substituting airfor water on the hull bottom; fourth, by directing the current flow inone direction or the formation of a secondary fluid streamline under thehull bottom harmonious in line to the hull and its forward motion,thereby reducing the adhesive grip of the combined fluids to the hullbottom to an absolute minimum, thus allowing boat A to steadily andsmoothly ride forward and increasing the efiiciency of the powerexpended.

The reason of the difference and argument for what I accomplishwill'appear as I proceed. a

The two concave surfaces 5 on opposite sides of the cutwater 3 spiraldownwardly with a graduated radius of curvature, the concavitydiminishing toward the terminus of the planing angle, at the flat bottom4 or lower surface of the air outlet 23. Viewing the front end of thebow we see nose 2 above cutwater 3 and the curved concave surfaces 5.See Figure 8. From nose 2 the edges 2a of the boat curve around as seenin plan View in Figure 1. The bottom edges of side sections 2a curvedownwardly until they merge into the bottom edges 26 of the aft planingsurfaces 25. As seen in Figure 8 the concave surfaces 5 are graduatedwith a radius of curvature as they recede from nose 2 to the flat bottom4 below outlet 23, at the terminus of the planing angle. The changingshape of the different sections of the concave surfaces 5 isbrought outin the diagrams in Figures 11 and 12, which indicate the sectionalcurves at various points. Thus in Figure 12 the dotted curves indicatethe shape of the concavities 5 at the extreme front,as viewed in Figure8. Various points in the length of the concave channels have beenselected and indicated by the vertical lines 6, f, g, and h; and fromthe points where these lines intersect the curved surfaces of thechannels 5 I have drawn horizontal lines respectively, as lines e f 9and k These lines in Figure 12 show the position of curves e f 9 and kwhich represent the cross sections of the concave showing the relativegraduation of curvature at the points out by the vertical lines.

In this diagrammatic way I show that the rather sharp curve at theextreme front gradually merges into section after section of lessercurvature until the flat horizontal section 4 is reached, at theterminus of the planing an 1e. This is only one example, and given y wayof illustration merely, since the concave surfaces may vary widely inshape, as also in'number, for there may be one or several of them curvedout or in or longitudinally or otherwise.

In the front portion of the how 2 is an air chamber 16, one or more,with a front opening 6, or window, which is equipped with a series ofpivoted shutters 17 operated by a connection 18 provided with a handle19 at the instrument board 15. Thus we have'an air chamber which islargest at the front end of the bow where the opening 6 furnishes an airoutlet controlled by the cover composed of shutters 17, which may beopened more or less at will. The inner smaller end 20 of the chamber 16communicates with the fan chamber or casing 21 which has a curved lowerend 22 at the bottom of the hull which is formed with an air deliverymouth 23, that is thin and wide and preferably in the form of a step asit were and the bottom of the hull and into the inverted V type channelas indicated by arrows F, F, formed by the after planing surfaces, whilethe water, with the.

forward movement of the hull glances or grazes the under side 4 of theair outlet at 23.

However, I do not wish to be confined to an outlet step. It ispreferable and has been found eflicient but the air outlet as well asthe air inlet may obviously be widely varied. The air travels around thehull, top, bottom and sides. vary widely and still retain theefficiencyof a streamline hull. The air intake in the bow may be throughone or several openings, to

The streamlines of the hull may allow the head wind pressure at the bowor point of greatest resistance to the forward movement of the hull, toflow or be absorbed into the air chamber and through the fan, if one isused, to be passed through the exit opening on the bottom of the hull inlarge enough quantities to form a stream of airv a percentage of thewater under the hull.

The deflection of the air may be accomplished in a variety of ways.Pressure through the opening in the bottom of the hull may be regulatedand controlled by means of a variety of air compression or blowerdevices, such as blower or compression fan wheels, or other types ofcompression devices. The type of fan wheel at 12 is of the blade typerevolving ina plenum chamber.

The air deflected under the hull has a lifting action, as well asfunctioning as a lubricant to reduce friction and turbulence of liquidon the hull bottom. It is a most important feature of my invention thatair or fluid pressure taken in through an opening in the hull of theboat and following through an opening in the water side of the hull addsbuoyancy to the hull in motion and exerts a lifting power, which aidsthe hull in quickly and easily attaining a planing positlon or positionin the liquid, offering the least resistance to its forward motionthrough fluid and liquid. The central portion of the air surfacedeflected downwardly joins the surface of the water underneath the hull.See Figure 4.

If air pressure were thus used only to help the hull to rise to aplaning position on the water, this could be done without involving theother principles of the invention, in regard to the location and kind ofintake, the placing of an air compression unit and dif ferent kinds andshapes of air exit openings, all of which the water surface serves as aseal. The boat I have shownand described is a type of construction thathas both buoyand a continuous flow of air under the The bow from thenose 2 to the air outlet 23 is partially in the water when the hull isstationary. When the hull moves forward, the concave planes 5 on eitherside of tho cutwater 3, with the air of the lifting power, or buoyancy,of the air stream underneath the hull bottom, cause the hull to attain aplaning position, or position in the fluid and liquid offering the leastresistance to its forward progress, owing to the tendency of the currentflow in the fluid and liquid to move outwardly from the central outwater3 and inwardly from the edges of the above surface 4 on line a, a. Theair under concavities of planing surfaces 5 toward line the concave bowplaning surfaces meets the water at this point and forms a surface ofcharged water, which adds itself to and forms j the underseal to the airstream'formation under the hull body from the air exit to stern.

The under surface of the hull may have a. variety of forms of a channeldesigned to keep the air under the hull, the water being used as a sealfor the air under the hull, the sides of the channel or channels beingso arranged that the air is delivered from the air exit on the bottom ofthe hull in a stream formation toward the stern and out from underneaththe hull directly aft of the stern.

The channel is angular, its central side being determined in relation tothe planing angle of forward surfaces, size of air exit on the hullbottom, lifting capacity of air under this hull, weight of motive power,so that the point of least resistance to the exit of air from underneaththe hull is directly aft of the stern.

The aft bottom surfaces of the hull are so arranged that while being atype of stream line surface in itself directs the current flow of fluidand liquid into a secondary fluid stream line formation, also convertingturbulence in the liquid into skin friction. The aft planing surfacesextending from the air exit to the stern, are angularly set surfaces ofthe inverted V type bottom, the angle of the inverted V var ing from theair exit to the stern, it being atter and more obtruse where it receivesthe air and sharper and more acute at the stern where it discharges theair, and the flat sides of surfaces of this angular channel beinginclined from one end to the other, which inclination will have the rearend highest when the hull is at rest, but will assume an approximatelyhorizontal position when the hull is moving forward has attained a fullplaning position, to correspond with water line a, a, in Figures 2 and3.

The flat surfaces 25 of this inverted V shaped or angular channel 24have outer edges 26, 26, which are the bottom edges of the sides of thehull, and these edges are level with the lower side of the air exit 4.

The graduation in angle from air exit to stern is accomplished bytilting the apex of the angle of the surfaces. With the forward movementof the hull, water contacts with the aforesaid surfaces from the edges26 inwardly towards the air stream, as indicated at X, Figure 10, byarrows, sealing in the air stream. The upward and inward inclination ofthe angular surfaces of the inverted V forming a surface, whiledirecting the current flow in fluid and liquid longitudinally with thehull. The tendency of the liquid stream is to glance inwardly, whichtendency increases as the angle of the surfaces becomes more acutetoward the stern from edges 26, 26, towards the central air stream andthe surfaces opposed to the liquid being angularly placed, cause theliquid to glance on rather than strike directly at said surfaces, theair stream absorbing or dispersing said turbulence and converting thelatter into skin friction, thereby eliminating turbulence or hammerblows and back drag on the hull.

The graduated increase in the acuteness of angle of the planing surfacesfrom the air outlet to stern forms an angular surface so graduated thatwith the forward motion of the hull the action of the combined lateral(at G, G, Figure 7) and longitudinal angles of the planing surfaces andthe air stream, in which latter the current flow is directedmechanically, and causes the liquid to join and become part of thisgeneral stream formation causing the combined mass of liquid and fluidunder the hull bottom to become a fluid streamline formation with linesharmonious to the lines of the hull.

This harmony of line established between hull formation and the surfaceover which it rides, the turbulence or eddy flow in the liquid havingbeen absorbed or dispersed by the lighter fluid mass of air,'reducesfriction on the hull bottom to an absolute minimum, and as the greaterpart of this efliciency is gained without the aid of motive power, adecided increase in the efiiciency of power expended'is the result.

Generally speaking, a streamlined body is one shaped to preventturbulence in the fluid through which it passes and directly aft in itswake. The bottom surfaces of the hull area streamline formation, but soformed that a reverse or secondary fluid streamline formation is causedin the fluid and liquid .over which the aforesaid surfaces ride. Thewake is discharged from underneath the hull directly aft of the stern,and disregarding the action of the propeller on the liquid. The wakebecomes the concave trailing edges or tail of the fluid streamline mass,rapidly disappearing as the liquid is heavily charged 7 with. air.

The air exit at 23 discharges air into the V-channel which is shallow atthat point and whose centre line is at 24. This channel varies in itsangle from the outlet 23 where it is quite flat and obtuse to the rearend where it is more acute. This has been plotted in a generaldiagrammatic way in Figures 13 and 14, so as to show the variation inthe angles. The vertical lines 6, 0, and (Z, intersect the bottom of thehull, and from the intersecting points run respectively the horizontallines 6 0 and d, which in Figure 14 meet the angle line and show how theplanes vary in their angular relation to each other from end to end atthe inverted V'-channel. In this way the channel has a streamlinedformation. The degrees of the different angular lines are indicated atb", 0 and d in Figure 14.

I seek to utilize and extend this harmony of motion or streamlineprinciple in my hull construction and to add the advantages thereof tothe other features of my improvement.

What I claim is:

1. In marine craft, a hull, the bottom of which is provided with acutwater and forward concave planing surfaces at opposite sides of thecutwater, and aft planing surfaces forming an angular channel ofinverted V type, the angle of the channel being graduated in acutenessfrom end to end, in combination with means within the hull for receivingair pressure as the craft moves forward, and means having an outlet fordelivering air into said channel under the hull, and said channeldirecting the current flow in fluid and liquid with a secondary fluidstreamline formation.

2. In marine craft, a hull streamlined above the free-board, the bottomof which has a forward concave planing surface graduated from a concaveat the nose of the bow to flat at the terminus of the planing angle onthe hull bottom, aft planing surfaces extending from the terminus ofsaid angle to the stern, which latter is formed with angularly setsurfaces of inverted V-type graduating from flat at the aforesaidterminus of the planing angle to acute at the stern, and means withinthe hull for receiving and controllin fluid pressure and delivering itinto said 0 annel at a point contiguous to the flat bottom section.

3. In marine craft, a hull streamlined above the free-board the bottomof which is formed with a forward concave planing surface, concave atthe nose of the how, the concavity decreasing gradually toward theterminus of the planmg angle from terminus of angle aft to the stern,angularl set surfaces of inverted V type channel ormation graduatingfrom obtuse at said terminus to acute at the stern to direct a currentflow in fluid and liquid, as the craft moves forward longitudinallyunder the hull bottom so that all the wake is delivered from under thehull directly aft to the stem.

4. In marine craft, a hull, the bottom of which is divided into forwardand aft plan-- ing surfaces, the latter surfaces extending from theterminus of the forward secton to the stern in a channel formation, saidchan nel graduating from shallow at said terminus to deep at the stern,a means to cause the liquid to glance on said surface from side towardscenter of said channel while, with the forward movement of the hull,directing the current flow of liquid longitudinally under the hullbottom, as meansto reduce turbulence in the liquid and convert thelatter into skin friction.

5. In marine craft, a hull, the bottom of which is divided laterally bya step into forward and aft planing surfaces, combined with means withinthe hull for receiving head wind pressure and delivering and controllingsame through exit means located in the vertical side of said step, theforward planing section having a cutwater on opposite sides of whichwith a spiralling graduated radius of curvature the surfaces extend tothe edges of the hull sides, in a channel formation, the outer edges ofthe channels being lower than the center of the channels, the curvatureof said channels extending from the nose of the craft downwardly to theterminus of the planing angle, the lateral concavity of said channelsdiminishing toward terminus of said angle into the approximately flatbottom of said step, as means to direct the current flow of fluid andliquid longitudinally with said channels and under the bottom of saidstep as a seal to air delivered from head Wind pressure to the aftplaning surfaces.

6. In marine craft, a streamlined hull above the freeboard, means withinthe hull for receiving head wind pressure as the craft moves forward,means for regulating quantity of air entering receivlng means, means forincreasing and diminishing a pressure in said receiving means, means fordelivering said air pressure to the exterior bottom surface of the hull,which latter surfaces are a type of streamline formation, so placed thatan inverted channel is formed on the hull bottom, the graduationlaterally and longitudinally of said surface sloping to form saidchannel that with the forward movement of the hull a current will flowlongitudinally sternward is caused in fluid stream and liquid in asecondary streamline formation harmonious in line to the aforesaidbottom surfaces, as means to convert turbulence in the liquid into skinfriction and further reduce said friction by the harmony of motionestablished between the hull and fluid and liquid surface over which itrides.

7. In marine craft, a hull, the bottom of which is divided into forwardand aft sections by a step, in combination with means within the hullfor receiving head wind pressure and discharging same through air exitmeans in the vertical side of said step, the aft bottom section formingan inverted channel, the lateralangle having its apex at the keel lineof the hull and they edges joining the sides of the hull level with thebottom of the aforesaid step, the longitudinal angle tilting upwardly onthe keel line of the hull from step to stern, causing the lateral angleto be obtuse at 'the step and graduating to more acute at the stern,said combination of angularly arranged surfaces, as means for holdingthe air current derived from means within the hull to a streamfoundation from step to stern while the said lateral angle of surfacescauses an angularinward pressure on the liquid surface and theturbulence, hammer blows and eddy motion in the liquid caused by theforward momentum of the hull glance inwardly on said surface to beabsorbed and'disintegrated by the air stream, the combined mass of fluidand liquid being formed by the longitudinal angle of said surfaces witha current fiowlongitudinally with the channel towards the stern,theincrease in acuteness of angular surfaces toward the stern forming agraduated increase in angular pressure exerted on said fluid and liquid,as means to cause the aforesaid current flow to form a secondary fluidstreamline formation, thereby eliminating side wake and turbulence influid and liquid aft, and delivering the fluid and liquid from under thehull directly aft of the stern, this wake form-' ing the tail of thefluid streamline formation.

8. In marine craft, a hull with streamlined free-board, the bottom ofwhich from the stern forward is an inverted channel, the

apex of which is higher than the hull bottom adjacent to the forwardterminus, the sides extending downwardly from the apex to the edges ofthe channel, said edges being continuous with the hull forward of thechannel terminus, said channel being in combination with means withinthe hull for receiving fluid and delivering fluid under pressure intosaid channel, which is graduated laterally and longitudinally todirectthe current flow of fluid and liquid, with the forward motion ofthe hull, into a secondary streamline formation, coordinating in motionwith the fluid stream passing over the freeboard surface of the bull toserve as means to economically convert turbulent drag into viscousorskin friction and establish a harmony of motion between the fluid andthe liquid in which the craft is immersed.

9. In marine craft, a hull, the bottom of which is an inverted channelwith right tom and continuing to the stern with keel line continuing tothe stern above the chines, with the angle of the chines in relation tothe keel expanding to the stern and forming a right and left laterallyand longitudinally graduated planing surface on opposite sides ofthekeel, with the craft at full planing angles and chines depresseddownwardly at the stern, but with the keel line substantially parallelto the water surface at the stern, forming a central channelunobstructed by the depression of the hull at the stern due to planingwith two longitudinal suspension areas determined at the chines, thewhole serving as means to lubricate the hull by a mixture of air andwater under the hull bottom due to velocity head pressure having passedthe point of critical velocity and to form a fluid and liquid streamline formation longitudinally harmonius in line with the invertedchannel, with velocity head pressure forming the center and movingfastest, the wake forming the concave trailing edges,

the discharge being directly aft of the stern.

10. In marine craft, a hull, combined with air means within the hullhaving inlet and outlet means, the latter in connection with forward andaft planing surfaces of the hull bottom, the latter forming an invertedchannel from saidoutlet means to the stern, the right and left sidesfrom the chines to the keel being of longitudinally similardimensignature.

EDWARD E. BALDWIN.

sions, the longitudinal angle of the chines in I relation to the keelline expanding to the stern, the aforesaid air means developing suctionforward and static head pressure in said outlet means, said staticpressure being converted into velocity head pressure at the forward enolofsaid channel with the point of least resistance to its dischargelongitudinally central with the channel at the stern, as means to propelthe craft forward while forming fluid and liquid into a stream lineformation, all the wake being delivered directly aft of the stern.

'11. In marine craft, a hull, the bottom of which has forwardand aftplaning surfaces formed with right and left sections from chines to keeland longitudinally continuous and of similar dimensions, the forwardplaning surfaces extending from the nose with chines joined at the keelto form the forward leading edge, and extending downwardly and expandinglaterally to the width of the hull bottom, the keel continuing to thestern above the chines, the aft planing surfaces being in invertedchannel form, the longitudinal angle of the'chincs in relation to thekeel expanding to the stern. combined with means located in the forwardend of said channel for dischargin: fluid and gases under pressure,caused by the operation of means within the hull, and directing thevelocity longitudinally within the channel to the stern and forming thefluid. liquids, and gases into a stream line formation, all the wakebeing delivered directly aft of the stern and as means to propel thecraft forward.

12. In marine craft-,a hull, the bottom of which is divided intorightand left sections longitudinally of similar dimensions,

